Comparison of Stress Distribution on a Straight and Angulated Abutment of Different Internal Hex Connections – Finite Element Analysis

Context: Various internal connections of implant abutments show different stress distributions. To improve this, a newer Morse taper connection is introduced. This connection aims to harmonize stress distribution between the abutment and implant fixture, potentially enhancing long-term implant stability and reducing the risk of mechanical complications. Aims: This article compares stress distribution on straight and angulated implant abutments with Morse taper connection and conventional internal hex connections. It uses finite element analysis (FEA) to assess two internal connection designs: the internal hexagon and conical connection. The study aims to optimize implant success by understanding the effects of abutment design on stress distribution. Materials and Methods: Using FEA, four geometric three-dimensional models were constructed representing implants with internal hex connections on straight abutment (Model 1) and angulated abutment (Model 2), implants with Morse taper abutment connections on straight abutment (Model 3), and angulated abutment (Model 4). These FEA models were meshed using ANSYS software (version 12.0), and material properties were fed into the software. These models were subjected to forces, and stress distribution pattern was studied and compared. Statistical Analysis Used: ANSYS software to compare the results was used for statistical analysis. Results: Internal hex connector with straight abutments gave 62.3 MPa of stress whereas internal hex connectors with angulated abutments showed 78.9 MPa of stresses at the implant–bone interface. Morse taper connectors with straight abutment gave 128.8 MPa of stresses whereas Morse taper connectors with angulated abutments gave 135.0 MPa of stresses at the implant–bone interface. Conclusions: Morse taper connections showed lesser deformation and better stress distribution compared to the internal hex type of abutment connections. Overall stress in the straight implants was less compared to the angulated implants.